<template>
  <div class="app-container">
  <!-- 顶部Header 区域 -->
  <mt-header fixed title="黑马程序员 Vue 项目">
	 <span slot="left" @click="goBack" v-show="flag">
		<mt-button icon="back">返回</mt-button> 
		 </span> 
  </mt-header>
	
  <!-- 中间的 路由 router-view 区域 -->
	<transition>
	 <router-view></router-view>
	</transition>
  <!-- 底部 Tabbar 区域 -->
  <nav class="mui-bar mui-bar-tab">
			<router-link class="mui-tab-item-llb " to="/home">
				<span class="mui-icon mui-icon-home"></span>
				<span class="mui-tab-label">首页</span>
			</router-link>
			<router-link class="mui-tab-item-llb" to="/member">
				<span class="mui-icon mui-icon-contact"></span>
				<span class="mui-tab-label">会员</span>
			</router-link>
			<router-link class="mui-tab-item-llb" to="/shopcar">
				<span class="mui-icon mui-icon-extra mui-icon-extra-cart">
					<span class="mui-badge" id="badge">{{$store.getters.getAllCount }}</span>
				</span>
				<span class="mui-tab-label">购物车</span>
			</router-link>
			<router-link class="mui-tab-item-llb" to="/search">
				<span class="mui-icon mui-icon-search"></span>
				<span class="mui-tab-label">搜索</span>
			</router-link>
	</nav>
  </div>
</template>

<script>
	export default {
		data() {
			return {
				flag: false
			};
		},
		created() {
			this.flag = this.$route.path === "/home" ? false : true
		},
		methods: {
		goBack() {
			 // 点击后退
			 this.$router.go(-1)
			//   this.$router 是一个路由【导航对象】，用它 可以方便的 使用 JS 代码，实现路由的 前进、后退、 跳转到新的 URL 地址

		}	
		},
		watch: {
			"$route.path": function(newVal) {
				if (newVal === "/home") {
					this.flag = false;
				} else {
					this.flag = true;
				}
			}
		}

	};
</script>

<style lang="scss" scoped>
.mint-header{
  z-index: 99;
}
	.app-container {
		padding-top: 40px;  //让app组件能全部显示出来
		padding-bottom: 50px;  //使comment组件能全部显示出来
		overflow-x: hidden;  //隐藏多余的部分，不让滚动条显示出来
	}

	.v-enter {
		opacity: 0;
		transform: translateX(100%);  //从右边进
	}
	.v-leave-to {
		opacity: 0;
		transform: translate(-100%);  //从左边出来
		position: absolute;  //防止页面左右滑动的时候页面内容从下面上来（抖动）
	}

	.v-enter-active,
	.v-leave-active {
		transition: all 0.5s ease;
	}

	// 该类名，解决 tabbar 点击无法切换的问题
.mui-bar-tab .mui-tab-item-llb.mui-active {
    color: #007aff;
}

.mui-bar-tab .mui-tab-item-llb {
    display: table-cell;
    overflow: hidden;
    width: 1%;
    height: 50px;
    text-align: center;
    vertical-align: middle;
    white-space: nowrap;
    text-overflow: ellipsis;
    color: #929292;
}

.mui-bar-tab .mui-tab-item-llb .mui-icon {
    top: 3px;
    width: 24px;
    height: 24px;
    padding-top: 0;
    padding-bottom: 0;
}

.mui-bar-tab .mui-tab-item-llb .mui-icon~.mui-tab-label {
    font-size: 11px;
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
}
</style>
  

